As much as I like the look of the dragon hitting the tree and the pose that follows, I feel like there's a missing panel where the dragon's attack mixed with its forward momentum makes it do a flip. Or maybe I should have just had it hit the tree differently.

I suppose it doesn't really matter when you consider the distance between Justin and the Cannon in Grace's imagination should have made getting hit by the darn thing effectively instantaneous, not to mention the fact that it's Grace's imagination. Any physical inconsistencies can be blamed on her, such as how Justin's shirt got torn as a result of getting hit in the face by a book.

Dragon - Cannon Combo

For anyone who forgot the cannon and/or dragon's abilities, the cannon allows Tensaided to attack with any monster from his hand for one energy (regardless of that monster's cost), but that monster dies after the attack because, well, cannon. The dragon, meanwhile, has an ability that deals three damage to every monster when it dies.

So... BAM. Fire the dragon from the cannon, killing the dragon, activating its ability. This ability also apparently involves quoting Moby Dick.